Method of making a truck ladder

ABSTRACT

Two pairs of transversely-aligned longitudinally-spaced veebottomed notches are formed in the opposite edges of the midportion of an elongated flat sheet metal blank, the opposite edge portions of which are then bent perpendicular to the central portion thereof to form an elongated channel member. This channel member is then bent transversely along the center lines of each pair of notches to form a top step integral with two parallel side rails which are then interconnected at and above their lower ends by a pair of fixed channel steps secured thereto in vertically-spaced parallel relationship. A wider foldable step is pivotally mounted on the side rails below the top step and carries a pair of centrally-bored attachment pins which initially guide a drill in drilling pilot holes in the truck body side wall for subsequent enlargement to receive the attachment pins which then secure the ladder to the truck body.

United States Patent 1191 Loomis et a1.

1 1 METHOD OF MAKING A TRUCK LADDER [52] US. Cl. 29/434; 29/464; 29/476;

1 13/1 16 I [51] Int. Cl. B23? 11/00 [58] Field of Search 29/476. 464.155. 469,

[56] References Cited UNlTED STATES PATENTS 720.891 2/1903 Chamberlainet a1. 182/206 X 1.621.696 3/1927 Vernet 29/434 1.836.354 12/1931Abrams. 2.1 19.500 5/1938 Quigan.. 2.331.709 10/1943 Mayne 2.502.2283/1950 Miller 182/93 1 1 Sept. 30, 1975 Nystrom 182/93 X PrimaryEraminer-Charlie T. Moon [57] ABSTRACT Two pairs of transversely-alignedlongitudinallyspaced vee-bottomed notches are formed in the oppositeedges of the mid-portion of an elongated flat sheet metal blank, theopposite edge portions of which are then bent perpendicular to thecentral portion thereof to form an elongated channel member. Thischannel member is then bent transversely along the center lines of eachpair of notches to form a top step integral with two parallel side railswhich are then interconnected at and above their lower ends by a pair offixed channel steps secured thereto in verticallyspaced parallelrelationship. A wider foldahle step is pivotally mounted on the siderails below the top step and carries a pair of centrally-boredattachment pins which initially guide a drill in drilling pilot holes inthe truck body side wall for subsequent enlargement to receive theattachment pins which then secure the ladder to the truck body.

9 Claims. 10 Drawing Figures 1 I METHOD OF MAKING A TRUCK LADDER This isa division of our co-pending application, Ser. No. 405,826, filed Oct.12, 1973, for Truck Ladder.

SUMMARY OF THE INVENTION This invention particularly resides in theconversion of an elongated channel member with vee-notched flanges intoa ladder top step integral with parallel side rails which are thereafterinterconnected by channel lower fixed steps and an upper tiltable widerstep possessing centrally-bored attachment pins the bores of which serveas drill guides for drilling truck body pilot holes which aresubsequently enlarged to receive these attachment pins.

In the drawings,

FIG. lis a'front elevation, upon a reduced scale, of a truck ladder,according to one form of the invention;

FIG. 2 is a right-hand side elevation of the ladder shown in FIG. 1,with the upper and wider step in its extended position;

FIG. 3 is a vertical section taken along the line 3 in FIG. 1;

FIG. 4 is an enlargedhorizontal section through one of the side railstaken along the line 4-4 in FIG. 1;

FIG. 5 is an enlarged vertical section, taken along the line s s in FIG.1;

FIG. 6 is an enlarged top planview of the folding upper step of theladder shown in FIG. I, removed from the ladder;

FIG. 7 is a left-hand side elevation of the step shown in FIG. 6; I

FIG. 8 is an enlarged horizontal section taken along the line 88 in FIG.1;

FIG. 9 is an enlarged top plan view of one of the stationary steps; and

FIG. 10 is a top plan view upon a reduced scale of the elongated sheetmetal blank from which the top and side rails of the ladder are producedby subsequent bending operations.

Referring to the drawings in detail, FIG. 1 shows a truck ladder,generally designated 10, according to one form of the invention, asconsisting generally of an integral top and side rail unit 12 of flangedchannel crosssection to which are connected lower fixed steps 14 and anupper swinging step 16 pivoted to internal channel reinforcements 18.The top and side rail unit 12, as its name indicates, is composed ofvertically-elongated parallel side rails or stiles 20 joined integrallyat the upper comers 22 to the top member 24, the whole being formed in asingle piece as described more fully below. Thus, the top member 24serves as a bridge or cross member connecting the side rails 20 at theirupper ends.

Each side rail 20 and the top member 24 are of channel cross-section(FIGS. 4 and 5), each side rail 20 having an end wall 26 whichinterconnects the side walls 28. The side walls 28 at their free edgesare provided with narrow flanges 30 directed toward one another andseparated from each other by a gap 32. Similarly, the top member 24 isprovided with a top wall 34which interconnects opposite side walls 36and the latter at their free edges are provided with narrow flanges 38also directed toward one another and separated from one another by a gap40. The top member 24 (FIG. 5) is also provided, in its top wall 34,with spaced holes 42 having upwardly-projecting frusto-conical rims 44for providing an anti-slip constructionjThe side rails 20 and top member24 are joined to one another at their corners 22 and also along theoblique ends 46 and 48 respectively cut at angles of 45 degrees andwelded or otherwise firmly secured to one another at the locations46 and48 (FIG. I).

- The side rails 20'are also joined to one another at their lower endsand at a location spaced above the lower ends by the" fixed steps 14.The latterare also of channel cross-section with top walls 50 (FIG. 9)which interconnect side walls 52 -(FIG.' 3) from the lower edges ofwhich narrow flanges 54 project toward one another leaving a space orgap 56 therebetween. Each of the fixed steps 14 at the opposite ends ofits top wall 50 is provided with end extensions 58-which project outwardfrom thedotted'lines 60 through the gaps 32 and lower or 'upper notches62 or 64 formed in the flanges '30'of the side rails 20 (FIG. 10) intothe interiors 66 thereof, where they are welded or otherwise secured inplace.

The dimensions of the notches 62 and 64 are similar to those of the endextensions 58 of the fixed steps 14 in order to pass therethrough. Eachof the fixed steps 14, like the top member 24, is provided withlaterallyspaced holes 68 (FIG. 9) having frusto-conicalupwardly-projecting rims 70 for anti-slip purposes.

Each elongated internal channel reinforcement 18 (FIG. 8) has an endwall or web 72 interconnecting opposite side walls 74 but, unlike theside rails 20, top member 24 and fixed steps '14, has only a singleflange 76. The channel reinforcements 18 (FIGS. 1 and 3) extend fromslightly above the upper fixed step 14 to a location above the swingingstep 16. The swinging step 16 (FIGS. 6 and 7) has a horizontal plateportion punched at staggered intervals with holes 82 havingfrusto-conical anti-slip rims 84 and drilled near its rearward edgeswith holes 86 in which are mounted ladderattaching pins 88 with centraldrilling guide holes 87 therethrough for drilling pilot holes in theside rail or outer edge of the truck floor outside the sides or sideboards of the truck bed. These pilot holes are then used to drill holesthe size of the ladder-attaching pins 88 which are inserted therethroughand locked in place by cotter pins (not shown) through transverse holes89 near the ends of the pins 88. Depending from the forward edge of theplate portion 80 is a narrow flange 90 (FIG. 7) while from its oppositeends rise end flanges 92. Each end flange 92 is drilled'(FIG. 8) nearits inclined forward edge 94 with a hole 96 in which is mounted a headedpivot pin 98, the head 100 of which is welded or otherwise firmlysecured to its respective end flange 92. The end walls or webs 72 of thereinforcements 18 are provided with coaxial holes 102 adapted to receivethe opposite ends of a support rod 104 extending thereacross immediatelybehind the front flange 90 when the swinging step 16 is in itshorizontal or operative position. The forward flanges 30 of the siderails 20 are provided with notches 106 (FIG. 10) aligned with the holes102 to afford clearances for the adjacent ends of the rod 104. The endwalls or webs 72 of .the reinforcements 18 are also provided with holes108 adapted to be aligned with one another to receive the pivot pins 98during assembly, as described notches 64 and 106 are punched orotherwise formed extending inward from the opposite edges 112 of theblank 110. Partially V-shaped and partially rectangular or parallelnotches 114 are also formed in the same manner in longitudinally-spacedrelationship inward from the opposite edges 112 with their V-shapedportions 46 and 48 at forty-five-degree angles to the edges 112 and atninety-degree angles to one another. The rectangular outer portions 116,118 are formed simultaneously with the V-shaped portions 46, 48, so thatthe outline of each notch 114 thus resembles the end view of an ordinarybarn. Either at this time or previously, the holes 42 with theirfrusto-conical rims 44 are formed in the central section 120, whichultimately becomes the top member 24 of the ladder 10.

The blank 110 is then subjected to bending operations along longitudinalbending lines running between the corners of the end notches 62 to formthe flanges 30 at right angles thereto in a direction away from theplane of the paper in the drawing. This is conveniently done by rollingoperations in a conventional rolling mill, as is well understood bythose skilled in the metalworking arts. The shallow channel member thusformed is subjected to a second and similar rolling operation at thedepth of the inner vertices ofthe notches 114 along bending linesparallel to the previouslymentioned bending lines, thereby forming theside walls 28 of the channel member having the end wall 26 and flangedconfiguration shown in FIG. 4.

- The thus-formed flanged channel member is then subjected to transversebending operations along bending lines extending between the vertices ofthe notches 114, whereupon the side edges 46 and 48 come together asshown in FIG. 1 to form the integral top and 1 side rail unit 12 offlanged channel cross-section previotherwise secured in position.

, Meanwhile, as these bending operations proceed, the opposite ends ofthe support rod 104 are aligned with the holes 102 in the reinforcements18 and the pivot pins 98 are aligned with their respective holes 108, sothat, as the bending nears its end, the ends of the rod 104 enter theirholes 102 while the pivot pins 98 enter their holes 108. At the sametime, the upper fixed step 14 is also aligned with its notches 64 (FIG.in the flanges 30 of the side rails 20, so that as the bending .thereofnear its end. the opposite ends 58 of the upper fixed step 14 enter theinteriors 66 of the side rails so as to become seated therein. The lowerfixed step 14 is then welded into place in the lower notches 62, and theladder 10 becomes completely assembled as shown in FIG. 1.

Alternatively, the welding of one or both of the headed pivot pins 98can be deferred until the ladder has otherwise been assembled asdescribed above, after which the pivoted upper step 16 is moved into itsproper position between the side rails, as one of the previously-weldedpivot pins 98 is pushed into its respective hole 108 in the end wall 72of its respective retainer 18, whereupon the loose remaining pivot pin98 is pushed through the then-aligned opposite holes 96 and 108 andwelded to the adjacent end flange 92.

We claim:

l A method of making a multiple-step ladder adapted to be attached to atruck body, said method comprising forming from sheet metal an elongatedparalleledged blank, forming two pairs of transversely-alignedveebottomed notches in the opposite edge portions of said blank, saidpairs of notches being formed equidistant from the opposite ends of saidblank at locations corresponding to the intended locations of the endsof the top step of the ladder, bending the thus-notched opposite edgeportions of said blank perpendicular to the remainder thereof alongparallel longitudinal bending lines through the centers of said notchesto form a channel member having a central wall and parallel side walls,

bending said channel member along transverse bending lines through eachpair of said transverselyaligned notches into a central top step memberand a pair of parallel ladder side members perpendicular to said topstep member and integral therewith,

preparing a plurality of lower step members with lengths correspondingsubstantially to the distance between said central walls of saidopposite side members,

and securing the opposite end portions of said lower step members tosaid opposite side members within the channels thereof and in spacedparallel relationship to said top member.

2. A method of making a multiple-step ladder, according to claim 1,wherein said vee-bottomed notches have parallel outer edge portions, andwherein said bending of said opposite edge portions is performed onbending lines passing through the junctions of said veebottomed notchportions and said parallel edge portions.

3. A method of making a multiple-step ladder, according to claim 2,including the additional step of bending the outer longitudinal edgeportions of said side walls toward one another into co-planar flangeswith a gap therebetween.

4. A method of making a multiple-step ladder, ac-

cording to claim 1, including the additional step of fixedly securingsaid lower step members to said opposi-te side members.

5. A method of making a multiple-step ladder, according to claim 3,including the additional step of inserting the opposite ends of saidlower step members through the gaps in their respective adjacent sidemembers, and also through the parallel-edged outer portions of theirrespective adjacent notches.

6. 'A method of making a multiple-step ladder, according to claim 1,including the additional step of pivotally mounting an upper step memberon said opposite side members for tilting motion between positionsrespectively co-planar with and perpendicular to said opposite sidemembers.

7. A method of making a multiple-step ladder, according to claim 6,including the additional step of mounting truck body attachment elementsupon said upper step member in projecting relationship therewith, saidelements being adapted to be secured to the truck body.

8. A method of making a multiple-step ladder, according to claim 7,including the additional step of providing drill guide bores in saidattachment elements cording to claim 1, including the additional step offorming said lower step members in channel configuration prior tosecuring said lower step members to said opposite side members.

1. A method of making a multiple-step ladder adapted to be attached to atruck body, said method comprising forming from sheet metal an elongatedparallel-edged blank, forming two pairs of transversely-alignedvee-bottomed notches in the opposite edge portions of said blank, saidpairs of notches being formed equidistant from the opposite ends of saidblank at locations corresponding to the intended locations of the endsof the top step of the ladder, bending the thus-notched opposite edgeportions of said blank perpendicular to the remainder thereof alongparallel longitudinal bending lines through the centers of said notchesto form a channel member having a central wall and parallel side walls,bending said channel member along transverse bending lines through eachpair of said transversely-aligned notches into a central top step memberand a pair of parallel ladder side members perpendicular to said topstep member and integral therewith, preparing a plurality of lower stepmembers with lengths corresponding substantially to the distance betweensaid central walls of said opposite side members, and securing theopposite end portions of said lower step members to said opposite sidemembers within the channels thereof and in spaced parallel relationshipto said top member.
 2. A method of making a multiple-step ladder,according to claim 1, wherein said vee-bottomed notches have parallelouter edge portions, and wherein said bending of said opposite edgeportions is performed on bending lines passing through the junctions ofsaid vee-bottomed notch portions and said parallel edge portions.
 3. Amethod of making a multiple-step ladder, according to claim 2, includingthe additional step of bending the outer longitudinal edge portions ofsaid side walls toward one another into co-planar flanges with a gaptherebetween.
 4. A method of making a multiple-step ladder, according toclaim 1, including the additional step of fixedly securing said lowerstep members to said opposite side members.
 5. A method of making amultiple-step ladder, according to claim 3, including the additionalstep of inserting the opposite ends of said lower step members throughthe gaps in their respective adjacent side members, and also through theparallel-edged outer portions of their respective adjacent notches.
 6. Amethod of making a multiple-step ladder, according to claim 1, includingthe additional step of pivotally mounting an upper step member on saidopposite side members for tilting motion between positions respectivelyco-planar with and perpendicular to said opposite side members.
 7. Amethod of making a multiple-step ladder, according to claim 6, includingthe additional step of mounting truck body attachment elements upon saidupper step member in projecting relationship therewith, said elementsbeing adapted to be secured to the truck body.
 8. A method of making amultiple-step ladder, according to claim 7, including the additionalstep of providing drill guide bores in said attachment elements adaptedto precisely align a rotary drill while drilling pilot holes in thetruck body for subsequent enlargement into fastener holes for laddersupporting fasteners.
 9. A method of making a multiple-step ladder,according to claim 1, including the additional step of forming saidlower step members in channel configuration prior to securing said lowerstep members to said opposite side members.